Food prices have been soaring since 2001. But, as Sir John Holmes, the UN's senior humanitarian official, tells this newspaper, governments have been slow to react.

In recent weeks, Mexicans have marched over the cost of tortillas, Mauritanians have rioted over grain prices, Yemenis have paraded their hungry children.

But it is hard to see what any government can do. Commodity prices are rising, pushing up the cost of fuel and fertiliser.

China, for a long time having had a deflationary impact on the world by turning out cheap exports, is now sucking in raw materials so prodigiously that it is having the opposite effect. Ground once given over to the cultivation of grain is now being used for biofuels.

Western governments can, however, do two things. First, they can stop imposing restrictions on genetic manipulation, which is the best way to increase yield from finite terrain (and which reduces the need for pesticides into the bargain).

Second, they can scrap the EU's Common Agricultural Policy, instead allowing each state to make direct payments to its farmers. Doing so would cut the average family's food bill by around £20 a week.

More important, though, it would open Europe's markets, enormously boosting the economies of Third World countries.

Reform of the CAP was supposed to be granted in return for Tony Blair's renunciation of the British rebate in 2004 but, since that deal, the percentage of the EU budget devoted to agriculture has, in fact, increased.

As long as the EU keeps the system in place, it is causing needless poverty both within its borders and beyond, more than cancelling out the effect of its foreign aid programmes. The time has come to scrap the CAP.